This invention relates to an ink jet recording head wherein a piezoelectric element is formed via a diaphragm in a part of each of pressure generating chambers communicating with nozzle orifices for jetting ink drops and ink drops are jetted by displacement of the piezoelectric element, and an ink jet recording apparatus comprising the ink jet recording head.
The following two types of ink jet recording heads, each wherein a part of a pressure generating chamber communicating with a nozzle orifice for jetting an ink drop is formed of a diaphragm and the diaphragm is deformed by a piezoelectric element for pressurizing ink in the pressure generating chamber for jetting an ink drop through the nozzle orifice, are commercially practical: One uses a piezoelectric actuator in a vertical vibration mode in which the piezoelectric element is expanded and contracted axially and the other uses a piezoelectric actuator in a deflection vibration mode.
With the former, the volume of the pressure generating chamber can be changed by abutting an end face of the piezoelectric element against the diaphragm and a head appropriate for high-density printing can be manufactured, but a difficult step of dividing the piezoelectric element like comb teeth matching the arrangement pitch of the nozzle orifices and work of positioning and fixing the piezoelectric element divisions in the pressure generating chambers are required and the manufacturing process is complicated.
In contrast, with the latter, the piezoelectric element can be created and attached to the diaphragm by executing a comparatively simple process of putting a green sheet of a piezoelectric material matching the form of the pressure generating chamber and baking it, but a reasonable area is required because deflection vibration is used; high-density arrangement is difficult to make.
On the other hand, to solve the problem of the latter recording head, Japanese Patent Publication No. 5-286131A proposes an art wherein an even piezoelectric material layer is formed over the entire surface of a diaphragm according to a film formation technique and is divided to a form corresponding to a pressure generating chamber according to a lithography technique for forming a piezoelectric element separately for each pressure generating chamber.
This eliminates the need for work of putting the piezoelectric element on the diaphragm and the piezoelectric element can be created by the lithography method, an accurate and simple technique. In addition, the piezoelectric element can be thinned and high-speed drive is enabled.
In this case, with the piezoelectric material layer provided on the whole surface of the diaphragm, at least only upper electrodes are provided in a one-to-one correspondence with the pressure generating chambers, whereby the piezoelectric element corresponding to each pressure generating chamber can be driven. However, it is desirable that each active part of piezoelectric element consisting of a piezoelectric layer and upper electrode is formed so as not to be beyond the pressure generating chamber because of problems of the displacement amount per unit drive voltage and stress placed on the piezoelectric layer in the portion straddling the portion facing the pressure generating chamber and the outside thereof.
Then, a structure is proposed wherein the piezoelectric element corresponding to each pressure generating chamber is covered with an insulation layer and the insulation layer is formed with windows each for forming a connection part to a lead electrode for supplying a voltage for driving each piezoelectric element, which will be hereinafter referred to as contact holes, in a one-to-one correspondence with the pressure generating chambers, and the connection part of each piezoelectric element and lead electrode is formed in the contact hole.
However, in the structure wherein the contact holes for connecting the upper electrodes and the lead electrodes are made, the whole film of the portion where the contact hole is made becomes thick and the displacement characteristic is degraded.
With the ink jet recording head as described above, a structure wherein the diaphragm in the portion corresponding to both sides of the piezoelectric element is thinned is proposed to improve the displacement efficiency provided by drive of the piezoelectric element. However, if large displacement is thus provided, particularly the tendency of destruction of a crack, etc., to easily occur in the proximity of the contact hole is promoted.
Further, the problems easily occur particularly if a piezoelectric material layer is formed according to a film formation technique, because the piezoelectric material layer formed according to the film formation technique is very thin and thus has low rigidity as compared with a layer where a piezoelectric element is mounted.
It is therefore an object of the present invention to provide an ink jet recording head for preventing destruction of a piezoelectric layer in the boundary between a pressure generating chamber and a peripheral wall, and an ink jet recording apparatus comprising the ink jet recording head.
In order to achieve the above object, according to a first aspect of the present invention, there is provided an ink jet recording head comprising: pressure generating chambers communicating with associated nozzle orifices; and piezoelectric elements provided in a one-to-one correspondence with the pressure generating chambers, each of the piezoelectric elements comprising a lower electrode provided in an area corresponding to the pressure generating chamber via an insulating layer, a piezoelectric layer provided on the lower electrode, and an upper electrode provided on the piezoelectric layer, each active area of the piezoelectric elements provided in an area facing the pressure generating chamber, and each inactive part of the piezoelectric elements not to be driven even having the piezoelectric layer continued from the active part.
In the first aspect, when the active part of piezoelectric element is driven, displacement in the boundary between the pressure generating chamber and the peripheral wall is suppressed by the inactive part of piezoelectric element and peeling of the piezoelectric film, occurrence of a crack, and the like are prevented.
In a second aspect of the present invention, crystal directions of the piezoelectric layer are oriented.
In the second aspect, the piezoelectric layer is formed in a thin film process, so that the crystal directions are oriented.
In a third aspect of the present invention, the piezoelectric layer has a columnar crystalline structure.
In the third aspect, the piezoelectric layer is formed in a thin film process, so that piezoelectric layer has a columnar crystalline structure.
In a fourth aspect of the present invention, the inactive part is extended from the inside of the area facing the pressure generating chamber to the outside of the area.
In the fourth aspect, the upper electrode of the active part or the lead electrode can be extended to the outside of the area facing the pressure generating chamber without forming a contact hole; wiring can be formed comparatively easily.
In a fifth aspect of the present invention, in the ink jet recording head in any of the first to fourth aspects, the lower electrode is removed to form the inactive part, and either the upper electrode or a lead electrode connected thereto is extended to the top of a peripheral wall of the pressure generating chamber through the inactive part.
In a sixth aspect of the present invention, in the ink jet recording head in any of the first to fourth aspects, an end portion of the upper electrode is positioned inside from an end portion of the lower electrode to be an end portion of the active part. The piezoelectric layer is provided on the lower electrode projecting to the outside from the end portion of the upper electrode, forming the inactive part, and is also provided outside the end portion of the lower electrode.
In the sixth aspect, a distance can be kept between the end portion of the active part and the end portion of the upper electrode, and a dielectric breakdown caused by concentration of an electric field, etc., at the end portion in the longitudinal direction of the active part is prevented.
In a seventh aspect of the present invention, in the ink jet recording head in any of the first to sixth aspects, the inactive part of piezoelectric element is provided continuously at one end portion in the longitudinal direction of the active part of piezoelectric element.
In the seventh aspect, peeling, occurrence of a crack, and the like at the end portion in the longitudinal direction of the active part of piezoelectric element are prevented.
In an eighth aspect of the present invention, in the ink jet recording head in the seventh aspect, the width of the inactive part at least in the proximity of a portion crossing the boundary between an end portion and the peripheral wall of the pressure generating chamber is narrower than the width of the active part.
In the eighth aspect, the displacement characteristic in the area facing the boundary between the pressure generating chamber and its peripheral wall is enhanced.
In a ninth aspect of the present invention, in the ink jet recording head in the seventh aspect, the width of the inactive part at least in the proximity of a portion crossing the boundary between an end portion and the peripheral wall of the pressure generating chamber is wider than the width of the pressure generating chamber.
In the ninth aspect, the rigidity of a diaphragm in the proximity of the end portion of the pressure generating chamber is held high and destruction of the diaphragm by driving the active part is prevented.
In a tenth aspect of the present invention, in the ink jet recording head in any of the first to ninth aspects, a displacement suppression layer for suppressing displacement of the active part is provided in an area facing the boundary between the active part and the inactive part.
In the tenth aspect, displacement of the active part at the end portion thereof is suppressed and destruction of the diaphragm by driving the active part is prevented.
In an eleventh aspect of the present invention, in the ink jet recording head in any of the first to tenth aspects, the lower electrode is provided continuously to the area facing partitions on both sides in the width direction of the pressure generating chamber and adjacent pressure generating chambers.
In the eleventh aspect, the rigidity of the diaphragm at both end portions in the width direction of the pressure generating chamber is held high and the durability of the diaphragm is enhanced.
In a twelfth aspect of the present invention, in the ink jet recording head in any of the first to tenth aspects, the inactive part is provided in one longitudinal end portion of the piezoelectric element. The lower electrode is provided so that both end portions in the width direction of the lower electrode are positioned in the pressure generating chamber together with both end portions in the width direction of the piezoelectric layer, and is extended from the other longitudinal end portion of the piezoelectric element to the top of the peripheral wall of the pressure generating chamber.
In the twelfth aspect, a distance can be kept between the end portion of the active part and the end portion of the upper electrode, and a dielectric breakdown caused by concentration of an electric field, etc., at the end portion in the longitudinal direction of the active part is prevented.
In a thirteenth aspect of the present invention, in the ink jet recording head in any of the first to eleventh aspects, the area facing the pressure generating chamber other than the inactive part is covered with the lower electrode.
In the thirteenth aspect, the end portion of the lower electrode does not exist in the surroundings of the lower electrode patterned in the pressure generating chamber, thus discharge is hard to occur and a dielectric breakdown of the piezoelectric layer is prevented.
In a fourteenth aspect of the present invention, in the ink jet recording head in any of the fifth to thirteenth aspects, the width of the removed lower electrode below the inactive part is narrower than the width of the pressure generating chamber.
In the fourteenth aspect, a dielectric breakdown of the piezoelectric layer is prevented without degrading the rigidity in the proximity of the end portion of the pressure generating chamber.
In a fifteenth aspect of the present invention, in the ink jet recording head in the thirteenth aspect, the inactive part is extended from a substantially central part of the pressure generating chamber in the longitudinal direction thereof on one peripheral wall in the width direction of the pressure generating chamber.
In the fifteenth aspect, a voltage can be applied to the central part in the longitudinal direction of the active part and the drive loss of the active part is suppressed.
In a sixteenth aspect of the present invention, in the ink jet recording head in any of the thirteenth to fifteenth aspects, the removed portion of the lower electrode below the inactive part is shaped substantially into a circle.
In the sixteenth aspect, the electric field applied to the part between the upper electrode and the lower electrode in the boundary between the end portion and peripheral wall of the pressure generating chamber is dispersed more widely and a dielectric breakdown of the piezoelectric layer is prevented.
In a seventeenth aspect of the present invention, in the ink jet recording head in any of the thirteenth to sixteenth aspects, the direction in which a margin of the upper electrode crosses from the top of the lower electrode to the top of the lower electrode removed portion is different from the direction in which the upper electrode is extended to the top of the peripheral wall of the pressure generating chamber.
In the seventeenth aspect, the electric field applied to the part between the upper electrode and the lower electrode in the boundary between the end portion and peripheral wall of the pressure generating chamber is dispersed reliably and a dielectric breakdown of the piezoelectric layer is prevented reliably.
In an eighteenth aspect of the present invention, in the ink jet recording head in any of the first to seventeenth aspects, the width of the lower electrode in a portion facing the boundary of the active part and the inactive part is narrower than any other portion.
In the eighteenth aspect, a dielectric breakdown between electrodes in the portion where the piezoelectric layer and the upper electrode are extended from the inside of the area of the pressure generating chamber to the outside of the area.
In a nineteenth aspect of the present invention, in the ink jet recording head in the eighteenth aspect, at least the distal end of the narrowed portion of the lower electrode is narrower than the piezoelectric layer and the upper electrode of the inactive part.
In the nineteenth aspect, at least the distal end of the narrowed portion is covered with the piezoelectric layer and insulated from the upper electrode reliably.
In a twentieth aspect of the present invention, in the ink jet recording head in the eighteenth aspect, the whole of the narrowed portion of the lower electrode is narrower than the piezoelectric layer and the upper electrode of the inactive part.
In the twentieth aspect, the whole narrowed portion is covered with the piezoelectric layer and the narrowed portion of the lower electrode and the upper electrode are insulated reliably.
In a twenty-first aspect of the present invention, in the ink jet recording head in the eighteenth aspect, the width of the narrowed portion of the lower electrode is wider than that of the piezoelectric layer and the upper electrode of the inactive part. The distance between an end face in the width direction of the narrowed portion and an end face in the width direction of the upper electrode is about 10 xcexcm or less.
In the twenty-first aspect, a predetermined or shorter distance is kept between the lower electrode and the upper electrode, whereby discharge between both the electrodes is prevented.
In a twenty-second aspect of the present invention, in the ink jet recording head in any of the fifth to twenty-first aspects, a discontinuous lower electrode discontinuous with the lower electrode is provided below the piezoelectric layer in the area facing the boundary between the pressure generating chamber and the peripheral wall thereof.
In the twenty-second aspect, the rigidity of the diaphragm in the portion where the piezoelectric layer and the upper electrode are drawn to the area outside the pressure generating chamber is held high and destruction of the diaphragm and the piezoelectric layer in the portion is prevented.
In a twenty-third aspect of the present invention, in the ink jet recording head in the twenty-second aspect, the discontinuous lower electrode is provided covering at least a margin of the pressure generating chamber.
In the twenty-third aspect, the rigidity of the diaphragm in the proximity of the end portion of the pressure generating chamber is held high and the durability is enhanced.
In a twenty-fourth aspect of the present invention, in the ink jet recording head in the twenty-second or twenty-third aspect, the discontinuous lower electrode is made discontinuous with the lower electrode by removing a lower electrode in the proximity of the end portion of the lower electrode in the longitudinal direction of the pressure generating chamber so as to extend in a width direction of the pressure generating chamber.
In the twenty-fourth aspect, the spacing between the discontinuous lower electrode and the lower electrode can be made narrow and the rigidity of the diaphragm is held higher.
In a twenty-fifth aspect of the present invention, in the ink jet recording head in any of the twenty-second to twenty-fourth aspects, the discontinuous lower electrode is not electrically connected to any parts.
In the twenty-fifth aspect, the discontinuous lower electrode and the lower electrode are insulated reliably.
In a twenty-sixth aspect of the present invention, in the ink jet recording head in any of the twenty-second to twenty-fourth aspects, the discontinuous lower electrode is connected to a resistor so that time constant of the lower electrode becomes larger than that of a drive pulse for the piezoelectric element.
In the twenty-sixth aspect the discontinuous lower electrode and the lower electrode are insulated reliably and the discontinuous lower electrode is prevented from having an excessive potential.
In a twenty-seventh aspect of the present invention, in the ink jet recording head in any of the twenty-second to twenty-sixth aspects, a wiring lower electrode is provided for each piezoelectric element on the peripheral wall on which the discontinuous lower electrode is provided discretely from the discontinuous lower electrode.
In the twenty-seventh aspect, wiring can be drawn from the active part easily and efficiently.
In a twenty-eighth aspect of the present invention, in the ink jet recording head in any of the twenty-second to twenty-fourth aspects, the discontinuous lower electrode is separated for each active part in the width direction of the pressure generating chamber and each is connected to either the upper electrode of the corresponding active part or a lead electrode connected to the top of the upper electrode.
In the twenty-eighth aspect, the rigidity of the diaphragm in the portion where the piezoelectric layer and the upper electrode are drawn to the area outside the pressure generating chamber is held high and wiring can be drawn efficiently.
In a twenty-ninth aspect of the present invention, in the ink jet recording head in the twenty-eighth aspect, each discontinuous lower electrode and the lower electrode have a spacing to such an extent that they can be insulated from each other.
In the twenty-ninth aspect, each active part of piezoelectric element is driven reliably and the jet characteristic is held good.
In a thirtieth aspect of the present invention, in the ink jet recording head in the twenty-eighth or twenty-ninth aspect, an intermediate electrode having no connection with any parts is provided between the juxtaposed discontinuous lower electrodes.
In the thirtieth aspect, removal of the lower electrode can be minimized and the rigidity of the diaphragm can be held more reliably.
In a thirty-first aspect of the present invention, in the ink jet recording head in any of the twenty-second to thirtieth aspects, the piezoelectric layer is left at least in a part of the removed portion of the lower electrode situated in other than the area corresponding to the piezoelectric element.
In the thirty-first aspect, the discontinuous removed portion and the lower electrode are insulated reliably and reliability can be enhanced.
In a thirty-second aspect of the present invention, in the ink jet recording head in any of the first to thirty-first aspects, a remaining part made of the same layer as the lower electrode is provided on the partition on both sides of the pressure generating chamber in the width direction thereof.
In the thirty-second aspect, the lower electrode removal area lessens, thus the piezoelectric layer is formed in a substantially even film thickness on the lower electrode patterned.
In a thirty-third aspect of the present invention, in the ink jet recording head in the thirty-second aspect, outside the end portion of the lower electrode of the active part, a discontinuous lower electrode discontinuous with the lower electrode. The remaining part is extended continuously from the discontinuous lower electrode.
In the thirty-third aspect, the spacing between the lower electrode forming a part of the piezoelectric element and the remaining part can be made narrow and the piezoelectric layer is formed in a even film thickness more reliably.
In a thirty-fourth aspect of the present invention, in the ink jet recording head in the thirty-second aspect, the remaining part is provided continuously with the lower electrode forming a part of the piezoelectric element.
In the thirty-fourth aspect, the spacing between the lower electrode forming a part of the piezoelectric element and the remaining part can be made narrow and the piezoelectric layer is formed in a even film thickness.
In a thirty-fifth aspect of the present invention, in the ink jet recording head in any of the thirty-second to thirty-fourth aspects, spacing between an end face in the width direction of the lower electrode and an end face in the width direction of the remaining part is wider than the thickness of the piezoelectric layer and is narrower than the width of the lower electrode.
In the thirty-fifth aspect, the film thickness of the piezoelectric layer in the width direction thereof becomes substantially even and the piezoelectric characteristic is not degraded.
In a thirty-sixth aspect of the present invention, in the ink jet recording head in any of the thirty-second to thirty-fifth aspects, an longitudinal end portion of the piezoelectric layer is situated in the proximity of the end portion of the pressure generating chamber the side of which the lower electrode is extended to the top of the peripheral wall. The distance from that end portion to a part where the lower electrode extended to the outside becomes wider is wider than the thickness of the piezoelectric layer and is narrower than the width of the lower electrode.
In the thirty-sixth aspect, the film thickness of the piezoelectric layer in the proximity of the end portion in the longitudinal direction of the pressure generating chamber becomes even and if the piezoelectric layer is patterned, the lower electrode therebelow does not become thin.
In a thirty-seventh aspect of the present invention, in the ink jet recording head in any of the thirty-second to thirty-sixth aspects, the remaining part has a width which is 50% or more of the width of the partition between the adjacent pressure generating chambers.
In the thirty-seventh aspect, the remaining part is formed in a predetermined width, whereby the piezoelectric layer is formed in a even film thickness more reliably.
In a thirty-eighth aspect of the present invention, in the ink jet recording head in any of the thirty-second to thirty-seventh aspects, the lower electrode and the remaining part are formed in an area having a width of 50% or more of the area corresponding to the pressure generating chambers placed side by side and the partitions on both sides of the pressure generating chambers in the width direction thereof.
In the thirty-eighth aspect, the lower electrode and the remaining part are set to predetermined dimensions, whereby the film thickness of the piezoelectric layer becomes even reliably.
In a thirty-ninth aspect of the present invention, in the ink jet recording head in any of the thirty-second to thirty-eighth aspects, the lower electrode and the remaining part are formed in an area of 50% or more of all area of the channel substrate.
In the thirty-ninth aspect, the lower electrode and the remaining part are set to predetermined dimensions, whereby the film thickness of the piezoelectric layer becomes even reliably.
In a fortieth aspect of the present invention, in the ink jet recording head in any of the first to thirty-ninth aspects, the crystalline structure of the piezoelectric layer on the lower electrode is the same as that on the insulating layer.
In the fortieth aspect, the crystalline state of the piezoelectric layer formed on the insulating layer becomes the same as that of the piezoelectric layer formed on the lower electrode, so that cracks do not occur and an abnormal stress does not occur on pattern boundaries either.
In a forty-first aspect of the present invention, in the ink jet recording head in the fortieth aspect, crystal seeds becoming nuclei of crystal of the piezoelectric layer are formed on a surface of the insulating layer.
In the forty-first aspect, the crystal structure of the piezoelectric layer is aligned in one orientation and is substantially evenly formed owing to the crystal seeds and occurrence of cracks, etc., is prevented.
In a forty-second aspect of the present invention, in the ink jet recording head in the fortieth aspect, the crystal seeds are formed like islands.
In the forty-second aspect, the crystal of the piezoelectric layer is grown from the crystal seed formed like islands.
In a forty-third aspect of the present invention, in the ink jet recording head in any of the fifth to forty-second aspects, a second insulating layer is provided on the outside of the end portion of the lower electrode.
In the forty-third aspect, the piezoelectric layer does not become thin in the proximity of the end of the lower electrode and a dielectric breakdown of the piezoelectric layer caused by concentration of an electric field is prevented.
In a forty-fourth aspect of the present invention, in the ink jet recording head in the forty-third aspect, the second insulating layer has substantially the same film thickness as the lower electrode.
In the forty-fourth aspect, the level difference between the lower electrode and the second insulating layer is small and the piezoelectric layer of a substantially even film thickness can be formed thereon.
In a forty-fifth aspect of the present invention, in the ink jet recording head in the forty-third or forty-fourth aspect, the second insulating layer is made of an insulating material different from that of the insulating layer.
In the forty-fifth aspect, the second insulating layer delivers a function regardless of the type of insulating material.
In a forty-sixth aspect of the present invention, in the ink jet recording head in any of the fifth to forty-second aspects, the insulating layer includes a thick portion situated on the outside of the end portion of the lower electrode.
In the forty-sixth aspect, the piezoelectric layer does not become thin in the proximity of the end portion of the lower electrode, so that a dielectric breakdown of the piezoelectric layer caused by concentration of an electric field can be prevented.
In a forty-seventh aspect of the present invention, in the ink jet recording head in the forty-sixth aspect, the thick portion has substantially the same thickness as the lower electrode.
In the forty-seventh aspect, the level difference between the lower electrode and the thick portion is small and the piezoelectric layer of a substantially even film thickness can be formed thereon.
In a forty-eighth aspect of the present invention, in the ink jet recording head in any of the fifth to forty-second aspects, a tapering portion where film thickness of the lower electrode is gradually decreased toward the outside of the active part is provided at the end portion of the lower electrode.
In the forty-eighth aspect, the tapering portion is provided at the end portion of the lower electrode, thus the piezoelectric layer formed in the proximity of the end portion of the lower electrode does not become thin and a dielectric breakdown in the proximity of the end portion of the active part is prevented.
In a forty-ninth aspect of the present invention, in the ink jet recording head in the forty-eighth aspect, the tapering portion forms a slope where the film thickness of the lower electrode is gradually decreased.
In the forty-ninth aspect, the piezoelectric layer is formed along the slope of the tapering portion and the piezoelectric layer at the end of the active part does not become thin.
In a fiftieth aspect of the present invention, in the ink jet recording head in the forty-eighth aspect, the tapering portion is a part where the film thickness of the lower electrode is gradually decreased stepwise.
In the fiftieth aspect, the piezoelectric layer is formed along the form of the tapering portion and becomes substantially the same film thickness as any other portion.
In a fifty-first aspect of the present invention, in the ink jet recording head in the forty-eighth aspect, the tapering portion forms a slanting curved surface where the film thickness of the lower electrode is gradually decreased continuously.
In the fifty-first aspect, the piezoelectric layer is formed along the form of the tapering portion and becomes substantially the same film thickness as any other portion.
In a fifty-second aspect of the present invention, in the ink jet recording head in any of the forty-eighth to fifty-first aspects, the piezoelectric layer formed on the tapering portion is thicker than any other portion.
In the fifty-second aspect, concentration of an electric field, etc., on the piezoelectric layer in the proximity of the end portion of the active part does not occur and a dielectric breakdown is prevented.
In a fifty-third aspect of the present invention, in the ink jet recording head in any of the fifth to fifty-second aspects, both longitudinal end portions of the active part are formed into a similar structure.
In the fifty-third aspect, like the one end portion of the active part, the opposite end portion is also prevented from being destroyed.
In a fifty-fourth aspect of the present invention, in the ink jet recording head in any of the fifth to fifty-second aspects, end portions of the piezoelectric layer and the upper electrode define a distal end of the active part which is opposed end to the end continued to the inactive part. In the distal end is covered with a discontinuous piezoelectric layer discontinuous with the piezoelectric layer.
In the fifty-fourth aspect, the end portion of the active part is protected by the discontinuous piezoelectric layer and the piezoelectric layer and the upper electrode are prevented from peeling, etc.
In a fifty-fifth aspect of the present invention, in the ink jet recording head in any of the fifth to fifty-second aspects, end portions of the piezoelectric layer and the upper electrode define a distal end of the active part which is opposed end to the end continued to the inactive part. The distal end is fixed with an adhesive.
In the fifty-fifth aspect, the end of the active part of piezoelectric element is fixed and the piezoelectric layer and the upper electrode are prevented from peeling, etc.
In a fifty-sixth aspect of the present invention, in the ink jet recording head in any of the first to fifty-fifth aspects, the pressure generating chambers are formed in a silicon monocrystalline substrate by anisotropic etching. The lower electrode, piezoelectric, and upper electrode layers are formed by film formation and lithography method.
In the fifty-sixth aspect, ink jet recording heads each having high-density nozzle orifices can be manufactured in large quantities and comparatively easily.
According to a fifty-seventh aspect of the present invention, there is provided an ink jet recording apparatus comprising an ink jet recording head in any of first to fifty-sixth aspects.
In the fifty-seventh aspect, an ink jet recording apparatus improved in the head reliability can be provided.